Pneumatic door-check



Patented Deo. 4, 1883.

w m W. M M m m E. I. `BLNTl -PNEUMAMG DOOR. GHEGK.

(Model.)

VWTNEEEE cylinder, as in opening the door, the said valve UNITED STATES PATENT O-EEicE."

PNEUMATIC DOOR-CHECK.

l u SPECIFICATION forming part of Letters Patent No. 289,380, dated December 4, 1883.

Application filed May 19, 1883. (Model.)

To a/ZZ whom it may concern:

Be it known thatl, EUGENE I. BLOUNT, of Cambridge, county of Middlesex, State of Massachusetts, have invented an Improvement in 5 Door-Checks, of which the following description, in connection with the accompanying drawings, is a specification, like letters on the drawings representing like parts.

. My invention relates to a door-check or ap paratus for automatically closing the door without slamming it', and it has for one of its objects to enable the movements of the door 4to be morel perfectly controlled than by the devices heretofore employed.

The invention is embodied in an apparatus hayingan actuating-spring and an arm oplerated thereby with an oscillating movement `when the door is opened or closed, the said arm being connected, as hereinafter described, with the door and with a controlling or cushioning cylinder, to retard and regulate the movement of the said arm in closing the door. The end of the arm is connected with the door by jointed levers or connectingrods, and means are provided for adjusting the strength `of the spring when desired, and also for adjusting the cushioning effect of the cylinder,

` which contains a fluid and a piston, provided' with a valve, allowing the fiuid to pass through it when moving in one direction through the closing and causing the iiuid to be forced around from one to the other end ofthe cylinder through a suitable passage controlled by ya valve in the return movement of the said piston as in closing the door. The piston has a piston-rod connected with the spring-pressed arm that operates on the door, and the connections are so arranged that the leverage ofthe arm or power of the Spring acts `with n least advantage when the door is :widest opened, thus i causing` a rapid movement of t he door when it begins to close, the resistance o f the fluid at the same time operating with tiel least advantage, and as the door closes t he leverageof-the spring increases as well as t he force derived from the resistance ofthe iluid in the cylinder, so that the door is finally closed witha slow but powerful movement.

Figure l is a plan view of adoor-check em` bodying this invention; Fig. 2, apartial horizontal section thereof, showing the construction of the cushioning cylinder and piston 'an d the actuating-spring; and Fig. 3, a partial vertical sectionon line :r x, Fig. l.

The main actuatingspring a, shown as a spiral spring similar to those employed for driving Vtrains of wheel-work, is inclosed in a v case, b, having la foot or plate, b', by which` it may be fastened uponthe casing of a door, over the top of the door, a short distance from the hinge, as shown in Fig. 1. One end of the spring c is connected with the case Z), as

by the screw 2, and the other end is connected with a collar, c, provided with a groove, 3, to receive a pin or key connected with the spindle d, passing through the said case and provided with a ratchet, d, at one end, adapted to receive a key or wrench at its other end.`

moving in the direction of the arrow 4, Fig.

l., and thus through the collar c to strain the spring a.

By turning the spindle d by means of a crank or key, the initial force of the springamay be regulated as desired, and it will be seen that the force of the spring will always tendtc turn the arm 71, in the direction opposite to the arrow 4. `The end ofthe arm /L is connected by toggle-jointed levers 7c 7c with the door, the y said lever k being pivoted at 5 in a lug, m, fastened upon the door near the end. of the arm lines, Fig. l. As the hinge pintle or axis of the movement of the door does not coincide with the spindle d or axis of the movement of l the arm h, the levers k L separate as the door opens, and the distance of the point from the spindle d or fulcrum of the arm orleverh will h when the door is closed, as shown in full gradually increase, thus diminishing thelever- .2 asmaso y with one another, as would happen if the pivotal movement of the level` 7c on the arm h were not arrested, and in operation the arm 71, and

lever k move together as if both consisted of a when the door is nearly closed the crank hl2 single piece, except when, in opening the door to its fullest extent, the lever k may be arrested, and the lever k will then draw away from the arm h,- but in many instances the arm l1, and lever k may be made in a single piece. v

The lug m is also provided with a preferably yielding1 stop, m2, which engages the lever 7c when the door is sufficiently opened, thus preventing further movement of the lever 7c', and causing the lever 7c to turn on its `joint with the arm h away from the stop h.

The arm 7L is provided with a crank, hm, having a pin, h3, entering a slot in the slotted cross-head a of the piston-rod or, having a guide, n, at its other end connected with the case b, and also serving as a stop for the arm I. The piston-rod a extends into the regulating-cylinder f, and is connected with the piston o, having one or more ports or passages, y 7, controlled by a valve, p, shown in this instance as a flexible disk connected near its middle with the piston, and having its periphery overlying the ports.

By having the piston-rod act upon the lateral crank on the oscillating arm 71 it is possible to have the regulating-cylinder with its axissubstantially parallel with the door-frame, instead of at right angles thereto, as would be required if the said piston-rod were connected directly with the arm h.

The cylinder f is provided with an opening, 8, through which it is filled with a fluid, preferably oil or glycerine, to retard the movement of the said piston. Vhen the arm h is moved in the direction of the arrow 4L in opening the door, the piston moves through the cylinder from the position shown in Fig. 2, and the liquid within it then passes freely through the ports 7 forcing the valve p open; but when the piston begins to move in the other direction, under the action of the spring c, turning the arm 7L in the direction opposite to the arrow 4 in closing the door, the valve closes and the fluid no longer has a passage through the piston, but is forced about from one to the other end of the cylinder through a small passage, r, connecting the ends of the cylinder. 4

The end of the cylinder ltoward which the piston moves while the door is closing is provided with a series'of small ports, 6, at different distances from its end, and all in line with one another, so that their amount of opening may be controlled by a single valve, s, operated by a handle, t, at the rear end of the cylinder, to govern the flow of the liquid, and thus regulate the amount of its retarding effect upon the piston and connected parts. The piston, in finishing its stroke, covers the said ports one after the other, and thus gradually cuts off the flow of the liquid, effectually checking the movement of the door, so that it is impossible for it to slam against the casing.

It will be seen, referring to Fig. l, that is nearly at right angles to the line of movement ofthe piston-rod, and consequently thc retarding force of the liquid then acts with maximum leverage, thus checking the movement of the door and causing it to close without slamming, and at the same time the spring a acts, through the arm or lever h, with the maximum leverage, thus having the greatest power upon the door, as is necessary to close and latch it. In the movement of the arm 71 when the door is opened at about right angles to the casing, the crank-pin h" will travel through the slotted cross-head, with the crank nearly in line with the pistonrod, which is thus at or near its dead-center, and almostpowerless' to resist the movement of the arm h under the action of the spring, Y and the door consequently begins to close from its wide-open position, with very little retardation from the fluid in the regulatingcylinder, and will move 4rapidly until nearly closed.

I. claiml. In a door-check, the springactuated crank-arm 71 provided with the pin h3, combined with the piston-rod n, provided with the slotted cross-head n, in which slotted crosshead the said pin is operable to move the piston back and forth in thc regulating-cylinder, substantially as and for the purpose described.

2. The actuating -spring and mechanism for'transmitting its force to the door, combined with the vregulating-cylinder having a passage connecting its ends and a controllingvalve therefor, and the piston provided with ports through it and avalve controlling them, and its piston-rod operating upon the said mechanism actuated by the spring, substantially as described.

3. The actuating spring and mechanism for transmitting its force to the door, combined with the regulating-cylinder having a passage connecting its ends and a series of ports entering the said passage at different distances from one end of the said cylinder,

and a single valve controlling them, and the piston operating in the said cylinder, substantially as described.

4. The spring and arm actuated thereby with an oscillating movement, and provided with a projection and stop near its free end,

IOO

IIO

combined with the toggle-levers pivoted to- `tiznlly as described.

289,380 3 nl y gether, and admapted to be pvotaliy connected In testimony whereof Ihavc signed my neme Io with the door and arm, respectively, substalr to this specification in the presence of two subseribing witnesses.

5. The spring and arm 71., actuated thereby, combined With the toggledeversk lc', one connected with the said arm, md the lug m, connected With the door and provided with astop, i; Titnessesz m2, (3o-operating with the vother of the said 1e- I JOS. P. LIVERMORE,

vers, substantially as described. XV. H. SIGSTON.

EUGENE I. BLGUNT. 

